Barrel salt bath furnaces



Aug. 3, 1965 B. R. ANKERSEN BARREL SALT BATH FURNACES 3 Sheets-Sheet 1Filed Sept. 14. 1961 N a V. w

Aug. 3, 1965 B. R. ANKERSEN BARREL SALT BATH FURNACES 3 Sheets-Sheet 2Filed Sept. 14, 1961 3, 1965 s. R. ANKERSEN I BARREL SALT BATH FURNACES3 Sheets-Sheet 3 Filed Sept. 14, 1961 INVENTOR ems: R/GMRDANKEKSENUnited States Patent BARREL SALT BATH FURNACES Barge Richard Anirersen,32871 Chatham Lane, Birmingham, Mich.

Filed Sept. 14, 1951, Ser. No. 133,139 6 Claims. (Ci. 2266-35) Thisinvention relates to barrel salt bath furnaces and particularly to arotary barrel type salt furnace for melting or heating highly oxidizablealloys and materials.

There are many industrial situations where it is desirable to melt orheat readily oxidizable materials such as aluminum without the oxidationlosses normally encountered. For example, it is frequently desired tomelt aluminum chips, filings, turnings and the like scrap. Conventionalmelting methods are either too slow, too costly or the losses inaluminum through oxidation are too high to be economically feasible.Various attempts to solve such problems have been made but without anyreal success.

I have invented a furnace structure which will overcome these problems.By the use of my furnace, it is possible to continuously melt aluminumchips and similar fine scrap without excessive losses and without theexpensive techniques heretofore proposed.

I provide a cylindrical body portion, divider means separating the bodyportion into two cylindrical portions, ports in said divider spacedabout the periphery of said divider, radial vanes in the interior ofeach said cylindrical portion beginning adjacent the ports and extendinglengthwise of said portions, a frusto conical end on one of saidcylindrical portions, spaced chordal enclosed passages beginningadjacent each vane and extending toward the apex of the frusto conicalend, a trough extending into the apex to receive fluid from saidenclosed passages, burner means directing a flame axially into one ofsaid cylindrical portions and drive means rotating said body portion.

In the foregoing general description, I have set out certain objects,advantages and purposes of my invention. Other objects, advantages andpurposes of my invention will be apparent from a consideration of thefollowing description and the accompanying drawings in which:

FIGURE 1 is a longitudinal section through a furnace according to myinvention;

FIGURE 2 is a section on the line IIII of FIG-' URE 1;

FIGURE 3 is a section on the line III-III of FIG- URE 1;

FIGURE 4 is a section on the line IV1V of FIG- URE 1;

FIGURE 5 is a longitudinal section of a second embodiment of myinvention;

FIGURE 6 is a section on the line VI-VI of FIG- URE 5;

FIGURE 7 is a section on the line VIIVII of FIG- URE 5;

FIGURE 8 is FIGURE 5.

Referring to the drawings, and particularly to FIG- URES 1 through 4, Ihave illustrated a cylindrical furnace body It) having an outer metalshell 11 and a refractory lining 12. A refractory divider member 13separates the furnace body into two cylindrical portions 14 and I5.Spaced ports 16 at the periphery of the divider member 13 communicatebetween the two portions 14 aond 15. An axial opening 17 in the dividermember 13 carries a burner 18 directed axially of the furnace body.Radial vanes 19 are provided in portion 14 between the end Wall 20 anddivider wall 13 adjacent the ports therein. A frusto-conical end portion21 is provided at the end of cylindrical portion 15 having an opening 22therein.

a section on the line VIIIVIII of were Radial vanes 23 are provided onthe inner periphery of the cylindrical portion between the dividermember 13 and the frusto conical portion. The vanes are low and do notcascade the salt, they simply cause a rolling of salt. Spaced elongatedpassages 24 extend diagonally from the end of vanes 23 to opening 22 ofthe frusto conical end portion. These passages act to deliver fluid fromthe base of the vanes 23 to the opening 22. A trough 25 extends intoopening 22 and receives the discharge from passages 24. Trough 25connects with a rotary Well 26 having a discharge spout 27. The well 2'5is rotatable on guide rolls 28 in a frame 29 at the output end of thefurnace. A charging chute 30 is provided at the end of the furnaceopposite the frusto-conical portion to feed through annular opening 31into portion 14 of the furnace.

In operation, aluminum or like chips to be melted are fed from chute 30into portion 14 of the furnace. The furnace body is rotated on carrierrolls 31a and 3111 by a drive motor 32 acting through pinion 33 and arack 34 surrounding the outer shell of the furnace. The chips enteringportion 14 are immediately submerged by molten salt discharged by vanesas they rotate. The cascading molten salt carries the chips beneath thesurface of the salt so that they melt before any opportunity foroxidation has occurred. The metal which melts settles to the bottom andpasses through the ports in the dividing wall into portion 15 of thefurnace. Rotation of the furnace causes the molten metal to be liftedwhile the salt rolls over the vanes to leave only a'thin protectivelayer of salt on the metal. The metal passes along vanes 23 into thepassages 24 which deliver it to trough 25 along with a small amount ofsalt which acts as a protective layer throughout the processing steps.The molten metal passes into well 26 and the excess salt passes over lip25a back into portion 15 of the furnace.

Counter rotation of the barrel will prevent any discharge throughpassages 24 and provides a means for regulating the rate of discharge aswell as the level of molten metal.

The salt in the furnace is retained and used continuously as the heattransfer and protective media for the metal.

In the form shown in FIGURES 5 through 8 I have illustrated a furnace 40having anouter steel shell 41 and a refractory lining 42. A refractorydivider member 43 separates the furnace body into two-cylindricalportions 44 and 45. Spaced ports 16a at the periphery of the dividermember 43 communicate between the two portions 44 and 45. An axialopening 46 in divider member 4-3 carries a flue member 47 which extendsthrough portions 44 and end wall 51 and out of shell 41. A second divder wall 48 at the opposite end of the furnace body from member 43carries an axial burner 49. Radial vanes 59 are provided in portion 44between the end wall 51 and divider member 43 adjacent the ports inmember 43. A frusto-conical end, portion 52 is provided adjacent thesecond divider wall 43. The supply line 53 for burner 49 passes throughan opening 54 in this frusto-conical portion. Radial vanes 55 areprovided in the cylindrical portion between the divider members 43 and48. These vanes, like vanes 23 of FIGURES l3 are low and do not cascadethe salt and metal, they simply cause the salt to roll over the edge asa barrier. Spaced passages 56 extend diagonally from the end of vanes toopening 54 in the frusto conical end so as to discharge into trough 5'7mounted on a rotary Well 53 having discharge spout 59. The well 58 isrotatable on guide rolls 60 in frame 61 at the output end of thefurnace.

A charging chute 62 is provided at the inlet end of the furnace oppositethe frusto conical end. Metal chips Fatented Aug. 3, 1965 are fed intochute 62 by rotary feeder 63 on the end of a rotary drum dryer 64surrounding the stack 67 which receives the output gases from finemember 47. The metal is dried and preheated by feeding it into dryer 64through chute 68 and is discharged into furnace feed chute 62 by feeder63.

The furnace is rotated on rollers 70 in usual manner by motor 71 drivingrack 72 through pinion 73.

The operation of this embodiment is essentially the same as that ofFIGURES 1 through 3 with certain ob vious modification.

In the foregoing specification I have illustrated and described certainpreferred embodiments of my invent-ion, however, it will be understoodthat the invention may be otherwise embodied within the scope of thefollowing claims.

I claim:

1. A metal melting furnace for melting oxidizable metals and the likecomprising a cylindrical housing forming a cylindrical body portion,divider means transversely separating said body portion into twogenerally cylindrical parts, port means communicating through saiddivider between the two parts, radial vanes on the periphery of eachsaid parts extending lengthwise thereof, a frusto conical end portion onone of said cylindrical parts extend-ing to an apex outside thecylindrical housing and having an opening at said apex, spaced encloseddiagonal passages beginning and having a port adjacent each vane andextending to the apex of the frusto conical end and having a port atsaid apex, a trough extending into the apex to receive fluid from saidpassages, burner means directing a flame into said cylindrical portions,a fluid heat transfer medium in said cylindrical portions, feeder meansdelivering metal to be melted into the interior of the furnace and drivemeans rotating said cylindrical housing.

2. A metal melting furnace as claimed in claim 1 wherein the feedermeans delivers metals to be melted at the end opposite the frustoconical end into one part of the furnace, said one parthaving vanes ofsuflicient height to cause the fluid heat transfer medium to cascadeonto the metal entering the furnace.

3. A metal melting furnace for melting oxidizable metals and the likecomprising a cylindrical housing forming a cylindrical furnace bodyportion, divider means transversely separating said body portion intotwo generally cylindrical parts, one a metal receiving part and theother a metal retaining and heating part, port means communicatingthrough said divider between the two parts, radial vanes on theperiphery of each said parts extending lengthwise thereof, said vanes inthe metal receiving part being of a greater height than those of themetal retaining part, a frusto conical end portion on the metal heatingpart of said cylindrical parts extending to an apex outside thecylindrical housing and having an opening at said apex, spaced encloseddiagonal passages on the frusto conical end beginning and having a portadjacent each vane and extending to and having a port at the apex of thefrusto conical end, a trough extending into the apex to receive fluidfrom said passages, burner means directing a flame into said cylindricalportions, a molten salt bath in said cylindrical portion, feeder meansdelivering metal to be melted into the interior of the furnace and drivemeans rotating said cylindrical housing- 4. A metal melting furnace formelting oxidizable metals and the like comprising a cylindrical housingforming a cylindrical furnace body portion, divider means transverselyseparating the body portion of said housing into two generallycylindrical parts, one a metal receiving part and the other a metalretaining part, port means 3 tea,

communicating through said divider between the two parts, radial vaneson the periphery of each said parts extending lengthwise thereof, afrusto conical end portion on one of said cylindrical parts extending toan apex outside the cylindrical housing and having an opening at saidapex, spaced enclosed diagonal passages beginning and having a portadjacent each vane and extending to and having a port at the apex of thefrusto conical end, a trough extending into the pex to receive fluidfrom said passages, burner means directing a flame generally axially ofsaid cylindrical portions, from the apex of the frusto conical end, afluid heat transfer medium in said cylindrical portion, feeder meansdelivering metal to be melted into the interior of the furnace, saidfeeder means being in heat exchange relationship with the exhaust gasesfrom the furnace whereby to dry and preheat the metal being fed anddrive means rotating said cylindrical housing.

5. A metal melting furnace for melting oxidizable metals and the likecomprising a cylindrical housing forming a cylindrical furnace bodyportion, divider means transversely separating said body portion intotwo generally cylindrical parts, one a metal receiving part and theother a metal retaining part, port means communicating through saiddivider between the two parts, radial vanes on the periphery of eachsaid parts extending lengthwise thereof, a frusto conical end portion onone of said cylindrical parts extending to an apex outside thecylindrical housing and having an opening at said apex, spaced encloseddiagonal passages beginning and having a port adjacent each vane andextending to and having a port at the apex of the frusto conical end, atrough extending into the apex to receive fluid from said passages,burner means directing a flame axially of said cylindrical portions,from an axial opening in the metal receiving part, a fluid heat transfermedium in said cylindrical portion, feeder means delivering metal to bemelted into the interior of the furnace at the metal receiving partadjacent the burner and drive means rotating said cylindrical housing.

6. A metal melting furnace for melting oxidizable metals and the likecomprising a cylindrical housing, divider means transversely separatingsaid body portion into two generally cylindrical parts, port meanscommunicating through said divider between the two parts, radial vaneson the periphery of each said partsextcnding lengthwise thereof, afrusto conical end portion on one of said cylindrical parts extending toan apex outside the cylindrical housing and having an opening at saidapex, spaced enclosed diagonal passages beginning and having a portadjacent each vane and extending helically to and having a port at theapex of the frusto conical end, a trough extending into the apex toreceive fluid from said passages, burner means directing a flame axiallyof said cylindrical portions, a molten salt bath in said cylindricalportion, feeder means delivering metal to be melted into the interior ofthe furnace and drive means rotating said cylindrical housing.

References (Cited by the Examiner UNITED STATES PATENTS 2,768,075 10/56Sterental 7568 2,878,004 3/59 Saernan 26643 2,948,525 8/60 West et al.26624 2,987,391 6/61 Foster et al. 7565 FOREIGN PATENTS 692,076 5/53Great Britain.

MORRIS O. V/OLK, Primary Examiner.

RAY K. WINDHAM, Examiner.

1. A METAL MELTING FURNANCE FOR MELTING OXIDIZABLE METALS AND THE LIKECOMPRISING A CYLINDRICIAL HOUSINGS FORMING A CYLINDRICAL BODY PORTION,DIVIDER MEANS TRANSVERSELY SEPARATING SAID BODY PORTION INTO TWOGENERALLY CYLINDRICAL PARTS, PORT MEANS COMMUNICATING THROUGH SAIDDIVIDER BETWEEN THE TWO PARTS, RADIAL VANES ON THE PERIPHERY OF EACHSAID PARTS EXTENDING LENGTHWISE THEREOF, A FRUSTO CONICAL END PORTION ONONE OF SAID CYLINDRICAL PARTS EXTENDING TO AN APEX OUTSIDE THECYLINDRICAL HOUSING AND HAVINGING AN OPENING AT SAID APEX, SPACEDENCLOSED DIAGONAL